maybe its just me, but i dont think my pred has the snap it had when i bought it, sometimes when i rap on it fast it chokes a bit first before it takes off. the last time i filled it up i had to get some poor grade gas, so i added a can of octane booster too, but it just isnt like it was. i dont have any mods on th engine, just the spark arrestor pulled out of the factory exhaust. anyone have any ideas on what might be going on? and how to fix it?